Use Case Point Estimation
in [OOP]
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From: Tomasz on 22 Sep 2005 15:05 Thanks, I've heard of Function Points, unfortunatelly for some reason I've thought it is a somewhat dated method and thus I did not pay much attention. However now, I'm certainly going to check it. Tomasz
From: Tomasz on 22 Sep 2005 15:49 > I tend to be 95% to 100% accurate with mine - depends on the scenario. > When people deliberatly ask me for a guess, I've been known to tell > them to take the preverbial soak in the lake. At what stage? Do you mean your accuracy is 95-100% even before you have designed the system? Congratulations! How do you do that? What kind of projects are you working on? >> Sure we revise our estimate after each significant phase as we have >> much better idea of what we are trying to achieve. >> > It then becomes a matter of process improvement to change the > environment to have the better idea before you do the phase rather > than after. I actually prefer to revise assumptions and estimates after I gather more information or decide what I want to do and not before :) (I think we are talking about same thing). > In my earlier post I said that you normally provide two. The first > being the guess, the second after some form of analysis the contract. > > I dont think anyone in any industry would volunteer to do work without > knowing what it is first. Unfortunatelly in the part of world I currently live in, it is a common practice. The contract is normally based on very incomplete information, thus the second option is usually not possible until after you start working on it. > I doubt you'd very often come across a software development project > that is actually 'new' - that is, it hasnt been experienced by someone > else who can supply metric data. Sure it will not be 'new' for the industry, but it will be new for you and this is usually enough. You cannot use your historical data (or you have to use it with caution). I do not think that getting the metrics from other people will be as easy as you say, and even if you get them, you have to "translate" them into your way of estimation. > The other thing, when something is 'new' you can often relate it to > something else that is similar. This removes the need for guestimates > and puts things closer to the certainties. > > Finally, as with any contractual estimate, there is always the game of > 'overs and unders. That is, estimates average out. This usually helps, but does not eliminate the problem, especially when you are given very agressive schedule. >> anything about the variation in initial and final scope. It might as >> well >> be that more mature organizations are better at PR. > lol. Its a refined art, based on experience (which is historical > metrics for people if you think of it that way). So you say. It certainly has an effect. Financial sector has often made slimilar claims, but I have not seen a plague of billionaire stock brokers so far. And in their case the results are so much easier to verify and compare. > The CMM is pretty good, I've been using it for years. Biggest problem > is the initial effort for a level 2 organistion to move to a level 3 > capability is quite difficult for short sighted managers to cope with. > Especially in an industry where the average employment cycle for staff > is only 1.5 years. Thing is, mature organisations tend to keep their > staff longer, hence their processes and estimates become more refined. CMM seems to be very sensible to me as well, however for a small company, I think PSP/TSP should be quite fine. > After demonstrating the capability, I would give a talk in one of the > team meetings on the techniques I was using and how they worked. It > was always good for a bout of enthusiasm for a few weeks or so > (usually until the PM messed up and the project hit a crunch phase). Is there any change you have this "talk" written down? I'm sure it would make an be interesting read, especially that I can then ask the author more questions later. Tomasz
From: Phlip on 22 Sep 2005 16:22 Tomasz wrote: >> I tend to be 95% to 100% accurate with mine - depends on the scenario. >> When people deliberatly ask me for a guess, I've been known to tell >> them to take the preverbial soak in the lake. > > At what stage? Do you mean your accuracy is 95-100% even before you > have designed the system? Congratulations! How do you do that? What > kind of projects are you working on? I estimate way over, and then goof off until they are accurate. <a beat> ;-) -- Phlip http://www.greencheese.org/ZeekLand <-- NOT a blog!!!
From: AndyW on 23 Sep 2005 01:28 On 22 Sep 2005 12:49:29 -0700, "Tomasz" <tzajacz(a)softhome.net> wrote: >> I tend to be 95% to 100% accurate with mine - depends on the scenario. >> When people deliberatly ask me for a guess, I've been known to tell >> them to take the preverbial soak in the lake. > >At what stage? Do you mean your accuracy is 95-100% even before you >have designed the system? Congratulations! How do you do that? What >kind of projects are you working on? Analysis :) >>> Sure we revise our estimate after each significant phase as we have >>> much better idea of what we are trying to achieve. >>> >> It then becomes a matter of process improvement to change the >> environment to have the better idea before you do the phase rather >> than after. > >I actually prefer to revise assumptions and estimates after I gather >more information or decide what I want to do and not before :) (I think >we are talking about same thing). Analysis :) > >> In my earlier post I said that you normally provide two. The first >> being the guess, the second after some form of analysis the contract. >> >> I dont think anyone in any industry would volunteer to do work without >> knowing what it is first. > >Unfortunatelly in the part of world I currently live in, it is a common >practice. The contract is normally based on very incomplete >information, thus the second option is usually not possible until after >you start working on it. No Analysis :( .. .. .. > >Is there any change you have this "talk" written down? I'm sure it >would make an be interesting read, especially that I can then ask the >author more questions later. > Sorry no. I've never been literate enough to write stuff down - thats for educated people :) However, being bored with the industry, I am currently taking time out to get educated - so may learn to write it down one day :)
From: Nick Malik [Microsoft] on 24 Sep 2005 21:33
>>> I dont think anyone in any industry would volunteer to do work without >>> knowing what it is first. >> >>Unfortunatelly in the part of world I currently live in, it is a common >>practice. The contract is normally based on very incomplete >>information, thus the second option is usually not possible until after >>you start working on it. > > No Analysis :( > . Hi Andy, Perhaps you are not familiar with the context in which Tom is writing. If I understand correctly, he is involved in a consulting organization that bids on RFPs. The orgs that bid on RFPs are unique companies (or branches of a company). They have to be. The process demands it. In the RFP process, a government agency (city, county, state, or federal) will hire a firm to come in and perform analysis. That company will produce a report that identifies "what" the agency needs. The Agency will then put out a "Request for Proposals" which is essentially the report plus a lot of legal language describing the method by which bidders are allowed to ask questions. All questions must be in the open (in other words, if you ask a question, all bidders get to see or hear both the question and the answer). This can take place at a bidders conference, or questions may be submitted in writing. Then the bidding company makes a bid. If you overbid, you don't get the contract because someone more accurate will. If you underbid, you take a bath because you can legally be held to delivery, even if the money runs out. You NEED to get it right, and you will not get a chance to analyze anything. The company hired to do the analysis is usually barred from bidding, or even speaking with one of the bidding companies. You have a very narrow channel of information: the RFP itself and any past experience you have had with the systems in that organization. Analysis is not an answer in this context. You need a mathematical approach, one that you can place a bond on... literally. (I've known RFPs that require the successful bidder to post a bond, sometimes in the millions, to cover the agency in the case the bidder pulls out half-way through.) In this context, re-read Tom's questions, and actually answer them. I'm dying to see how you can get to 95% accuracy on a project over $100K in the RFP process. -- --- Nick Malik [Microsoft] MCSD, CFPS, Certified Scrummaster http://blogs.msdn.com/nickmalik Disclaimer: Opinions expressed in this forum are my own, and not representative of my employer. I do not answer questions on behalf of my employer. I'm just a programmer helping programmers. -- |